Briefing

Briefing

Yeti crabs

A recently discovered group of crustaceans called yeti crabs (genus Kiwa, order Decapoda) have added to the number of extraordinary and previously unknown species inhabiting the harsh, inhospitable environment around hydrothermal vents on the deep seafloor. So far, three species have been identified. Kiwa hirsuta was discovered in 2005 at a hydrothermal site south of Easter Island in the Pacific Ocean at depths of 2200 meters (7220 feet). Kiwa puravida was found in Pacific waters at depths of 1000 meters (3280 feet) off Costa Rica and described in 2011. Kiwa tyleri was located at two hydrothermal vent sites in the Antarctic Ocean at depths of 2400–2600 meters (7875–8530 feet) and described in 2015. Molecular and phylogenetic analyses have confirmed the placement of these species into a new family, Kiwaidae, of decapod crustaceans. See also: Arthropod evolution and phylogeny; Biodiversity; Census of Marine Life; Crustacea; Decapoda; Deep-sea fauna; Marine biological sampling; Oceanography

Measuring up to 15 centimeters (5.9 inches), the yeti crabs inhabit hydrothermal vent sites, which are discrete mounds and sulfide chimneys emitting hot fluids on the ocean floor. Dense biologic communities live on and around these hydrothermal structures because the hot fluids emanating from the Earth's crust warm the surrounding water temperatures to habitable levels. The warmer temperatures of these areas also allow an abundance of bacteria life to thrive, which in turn forms the base of the food chain for these unusual ecosystems. The bacteria provide the main diet for many marine creatures, including the yeti crabs, which have adapted morphologically in an extraordinary way to attract and capture these bacteria. Specifically, the yeti crabs possess dense, long, plumose setae (bristling hairlike structures) on the surfaces of their long appendages. Because the white or yellowish "furry" appearance of the setae reminded investigators of the legendary Yeti, the hairy abominable snowman of the Himalayas, the term yeti crab was adopted as the common name of this animal. Investigators have determined that most of the setae have clusters of chemosynthetic, sulfide-oxidizing bacteria living on them. Thus, the setae have been hypothesized to serve as gardens for growing the crabs' main food source (that is, the bacteria). This type of feeding strategy is a plausible one, as it has been used by a number of other crustaceans inhabiting hydrothermal vents and methane seeps. In addition, yeti crabs have been observed to scavenge for and consume mussel tissues. See also: Bacteria; Ecological communities; Hydrothermal vent; Marine ecology; Marine microbiology; Trophic ecology

Additional Readings

E. Macpherson, W. Jones, and M. Segonzac, A new squat lobster family of Galatheoidea (Crustacea, Decapoda, Anomura) from the hydrothermal vents of the Pacific-Antarctic Ridge, Zoosystema, 27(4):709–723, 2005

To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.

Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.

About AccessScience

AccessScience provides the most accurate and trustworthy scientific information available.

Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 39 Nobel Prize winners.

Features

MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology

115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms

3000 biographies of notable scientific figures

MORE THAN 17,000 downloadable images and animations illustrating key topics

ENGAGING VIDEOS highlighting the life and work of award-winning scientists

SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research

LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information